RV buying advice

Hey,
Debating buying an RV. Vague, I know.
So the general background: I am stationed in Alaska for the next few years. Returning next year and was looking at ways to get my dog up to Alaska from the lower 48 and decided on renting an RV and getting some buddies together and enjoying the drive out west and up north again. While looking into the rentals I naturally started looking at RVs in general. I have done a lot of road trips already and enjoy camping and life on the road. Trip from Georgia to AK last year with my dad was probably one of the best experiences I have had. While stationed in AK I am trying to explore as much of the state as I can since it is a once in a life time opportunity and there are so many unique places up there and I think an RV would make that easier to do with a dog (I drive a Wrangler and she is a large dog). Also it would be useful for the trip back to the lower 48 whenever that happens and then great for exploring in the next location. Budget wise, used seems to be the smarter option for me. I have rented an RV before and really enjoyed the experience, although it was only for a few days in college. Would be looking for a 3-5 person unit. My
Now that that's out of the way my main questions (trying to avoid common questions that I can dig through and find but any advice or thoughts for someone new to the RV world considering buying is very much appreciated):
- Any feedback or thoughts on buying from a place like El Monte or Cruise America
- Considerations on maintenance and potential storage costs
- Things to be wary of buying used
- RV considerations in extreme weather conditions
- mileage concerns
Hope this post doesn't ramble too far. Any feedback is appreciated. Thanks guys.